I check the two pair of arms of VTSC X Wing Luke and TAC X Wing Biggs figures, they seemed to look both the same size, the lower legs or feet from VTSC X Wing Luke looks great it has the ball jointed ankles.

the torso of VTSC X Wing Luke with a removable chest piece looks just right that has to be retooled to make it a little taller then luke's torso (VTSC X Wing Pilot) for a new X Wing Pilot figure and later reuse it to create all other rebel pilots from ANH and ROTJ (including Wedge).

they can make new upper legs/thighs and to be added to the feet of Luke X Wing VTSC

after they done made the figure of a new x wing pilot they can reuse the figure (with retooled torso and new thighs) to create all other rebel pilots luke wedge, the other x wing pilot (who came to luke and biggs from ANH), two other pilots fly the y wings from ANH, all other pilots from ROTJ.